In acute haematogenous multifocal osteomyelitis, infectious foci occur in several bones simultaneously due to haematogenous bacterial spread. Acute haematogenous multifocal osteomyelitis should be distinguished from chronic recurrent multifocal osteomyelitis (CRMO). We reviewed the medical records of three male adolescents of 15 years (range 13–16 years) with acute multifocal haematogenous osteomyelitis. All patients were athletes (soccer player, water polo player, practicing rowing). The mean duration of painful symptoms before seeking medical attention was 3 days. Osteomyelitis was confirmed by magnetic resonance imaging (MRI) and bone three phase scintigraphy. The lesions were at level of spine plus left femur in the first case, bilateral tibia and lumbosacral column in the second one, right foot plus left femur were interested in the third case. Two of the patients exhibited a spinal osteomyelitis, which is described as a common spinal affection in athletes. Blood cultures (in all patients) and culture of abscess drainage (in one case) were positive for Staphylococcus aureus (MSSA). Inflammatory indices were increased in all patients (mean values: WBC 15.130/mmc, CRP 19 mg/dl, and ESR 63,6 mm/h). Intravenous antibiotic therapy was prescribed for 19 days (range 13–33 days), followed by oral antibiotic therapy for a median of 18 days. After a median of 11 days, all patients clinically improved with resolution of fever and reduction of pain. Patients were discharged with oral antibiotic therapy after a median of 22 days hospitalization, and underwent a 16 months follow up. No patient reported sequelae. Differential diagnosis among multifocal acute osteomyelitis, septic arthritis, CRMO, juvenile idiopathic arthritis and/or reactive arthritis may be difficult. Previous studies reported that athletes are more at risk for osteomyelitis, but, to our knowledge, no case series of acute haematogenous multifocal infectious have been reported in competitive athletes. Staphylococcal outbreaks have been reported in sport players, as position, artificial grass abrasion, and body shaving are the main portal of bacterial entry. In conclusion, a diagnosis of acute multifocal osteomyelitis must be considered in a patient with fever and pain of several bones. A prompt hospitalization and an appropriate therapy reduce the morbidities and can help to avoid surgery

Acute Haematogenous Osteomyelitis (AHO) remains a cause of severe illness among children with the possibility of long-term consequences for growth and development. Previous research on sequelae from AHO rarely considers outcomes more than two years following treatment. This study aims to establish the quality of life of patients diagnosed with AHO in childhood up to 13 years after diagnosis, evaluating the impact on social, emotional, physical, and school function. Children treated for AHO between 2008–2018 at a tertiary referral centre in New Zealand were identified. PedsQL™ questionnaires were conducted via phone with either the child or primary caregiver and responses analysed. 40 patients met inclusion criteria, were contactable by phone, and consented to participate. The mean age was 7 years (range 0–15) and most were female (60%). Health related quality of life (HRQOL) was scored as a percentage with most participants scoring >80% (n=27). Those who do experience reduced quality of life following treatment for AHO were likely to complain of pain, stiffness, or anxiety. The impact of significant childhood illness on mental health was not adequately captured by the PedsQL™ but was highlighted in qualitative feedback. We conclude that the majority of children treated for AHO reported excellent health-related quality of life up to 13 years following treatment although an negative impact on mental health was reported using qualitative analysis. A refined scoring system is needed to assess the long-term impact of musculoskeletal infection

Acute osteomyelitis and septic arthritis are uncommon diseases in childhood that affect previously healthy children. A high index of suspicion, early diagnosis, initiation of appropriate antibiotic treatment and surgical intervention are essential for a good outcome. The aim of our study was to evaluate our approach, clinical signs and the outcome of the diseases. We retrospectively analyzed clinical, laboratory and microbiologic data in children hospitalized for acute haematogenous osteomyelitis or septic arthritis at the Department of Orthopaedic surgery in a 10-year period (from 2003 to 2013). Follow-up of outpatients was continued for at least 1 year or until the full recovery. Acute haematogenous osteomyelitis or septic arthritis were confirmed in 22 patients, 14/22 (64%) had osteomyelitis and 8/22 (36%) arthritis, 16/22 (73%) were boys. The mean patient age was 9,3 years (SD:3,5), the median of the hospitalization was 32 days (IQR:13 – 60 days). In children with osteomyelitis 10/14 (72%) had affected lower limb and in 4/14 (28%) the spine was affected. Six (80%) children had septic arthritis of the knee, hip joint was affected in one child and sacroiliac joint in one as well. We obtained blood cultures in 19/22 (86%) patients, bone biopsy was performed in 14/22 (64%). All infections were monomycrobial, Staphylococcus aureus was the most common pathogen, as expected. In one patient the cause of the osteomyelitis was Panton-Valentine leucocidin (PVL) producing S. aureus. The characterics are presented in Table 1. All affected children recovered completely. We observed 22 cases of pediatric bone and joint infections in a 10-year period. The most common pathogen was Staphylococcus aureus, as expected, althogh in more than half of cases no pathogens were found. One child suffered from osteomielitis caused by S. aureus strain producing PVL. We observed higher proportion of spine invovelment than previously reported in the literature

Aim. We report our ten year experience of primary haematogenous non-tuberculous spinal infection. Method. Retrospective case note review of 42 patients presented to our institution with primary spinal infection during 1995-2005 was carried out. Demographic data, timing and modes of presentation, investigations, and methods of treatment were analysed. The cost benefit of Home Intravenous Antibiotics Service (HIAS) was also investigated. Results. Mean age was 59.9 years (1-85) with almost equal gender distribution (M 20: F 22). Axial pain was universal. Pyrexia was seen in 62% and major neurological deficit in 10% of cases. Time from presentation to diagnosis averaged 19 days (range 0-172). Sensitivity for MRI and plain x-ray was 100% and 46% respectively. Blood culture was as sensitive as percutaneous biopsy in patients with pyrexia. Staphylococcus Aureus was the most common organism. Treatment ranged from intravenous antibiotics alone to combined anterior and posterior surgery depending on the presence or absence of significant abscess collection, neurological deficit and structural threat. Mean duration of intravenous antibiotics was 54 days (range 13-240). At mean follow up of 5.4 years (0.6-10.5) there was no mortality directly related to the infection. Recurrence rate was 14%. Significant past medical history (p=0.001), constitutional symptoms (p=0.001) and pyrexia at presentation (p=0.001) and possible male gender (p=0.01) were positively associated with recurrence. Although firm conclusions can not be drawn due to sample size, duration of symptoms (p=0.27) did not appear to affect the risk of recurrence. When inpatient days were subtracted from days on IV antibiotics for all the patients, HIAS was found to have saved a total of 940 inpatient days. Conclusion. In spinal infection, disease and patient characteristics dictate the management strategy. Longer antibiotic therapy in patients with positive risk factors for recurrence may be indicated. Finally, HIAS was cost effective in this group of patients

Aim

Melioidosis is a significant public health problem in endemic regions such as India. Lack of awareness, predominant empiric antibiotic use reducing culture yields, morphotypic variability of cultures and frequent misidentification by automated blood culture systems, pose myriad challenges in diagnosis and treatment. Through this series, we present our experience of Hematogenous Osteomyelitis with Burkholderia pseudomallei.

Aim

The gold standard treatment for late acute hematogenous (LAH) periprosthetic joint infection (PJI) is surgical debridement, antibiotics and implant retention (DAIR). However, this strategy is still controversial in the case of total knee arthroplasty (TKA) as some studies report a higher failure rate. The aim of the present study is to report the functional outcomes and cure rate of LAH PJI following TKA treated by means of DAIR at a long-term follow-up.

Aim

Acute hematogenous periprosthetic joint infection (AHI) is a diagnosis on the rise. The management is challenging and the optimum treatment is not clearly defined. The purpose of this study was to evaluate the characteristics of AHI, and to study risk factors affecting treatment outcome.

Aim

The incidence of hematogenous periprosthetic joint infections (hPJI) is unknown and the cases probably largely underreported. Unrecognized and untreated primary infectious foci may cause continuous bacteremia, further spread of microorganisms and thus treatment failure or relapse of infection. This study aimed at improving knowledge about primary foci and microbiological characteristics of this entity to establish preventive measures and improve diagnostic and therapeutic strategies to counteract hPJI.

In France, 5% of men and 7% of women aged more than 60 years have a joint prosthesis (JP). The incidence of H-PJI following BSI remains unknown (1–2). The aim of this study was to determine prospectively the clinical characteristics of patients with JP and the incidence of H-PJI following a BSI.

A prospective observational multicentric study was performed in two French General Hospitals, from December 2012 to April 2015. Each patient with JP, in whom a BSI was diagnosed, was evaluated prospectively by an ID specialist. Data regarding clinical and microbiological characteristics were collected. A follow-up by phone call was performed monthly during 6 months to determine the incidence of H-PJI following BSI.

During the study period, 97 patients of mean age ± SD of 82.1 ± 10.4 years were identified, with a predominance of women (n=61). Nineteen patients (20%) had neoplasia, and 32 diabetes mellitus (33%). Most patients had one (n=61; 63%) or two JP (n=29; 30%); with a predominance of hip arthroplasty (n=77; 79%). Predominant pathogens were E. coli (n=41; 42%), S. aureus (n=23; 23%) and S. pneumoniae (n=8; 8%).

At the onset of BSI, the JP was concomitantly infected in 10 (10.3%) patients (including 8 S. aureus, 1 E. coli and 1 P. mirabilis), thus 87 were studied for the incidence of H-PJI following BSI of another source. Among these 87 patients, no H-PJI was detected, with a complete 6-month follow-up available for 29 patients (34%), incomplete follow-up for 26 patients (30%), loss of follow-up for 3 patients (3%), and death occurring in 29 patients (34%). The comparison between the patients with no H-PJI detected (« No Event Group ») and the deceased patients (« Death Group ») showed that patients of the « No Event Group » had a lower rate of neoplasia (14% vs 34%; P=0.025).

Our preliminary results show that patients with JP in whom a BSI occurred were old, and had a high mortality rate. In our study, the incidence of secondary H-PJI appears to be low, since no event was detected during the follow-up. The incidence of H-PJI may have been underestimated due to the high mortality rate.

We would like to thank Dron Hospital and Bethune Hospital medical teams.

The authors declare that there are no conflicts of interest.

We present our experience of treating 57 cases of bone defects associated with chronic osteomyelitis (COM) and an algorithm for their treatment.

A retrospective analysis of our operation database revealed 377 patients treated for COM (2002–2010). 76 (20%) had bone defects, of these 57 had notes and x-rays available. The tibia was most commonly affected (63%), followed by the femur (21%). Infection control procedures included debridement, drilling and sequestrectomy. Long-term antibiotics were seldom used. Prerequisites to reconstruction surgery were; fully healed skin, absence of sequestrae on x-ray and no antibiotics for 2-months. Decision on the method of treatment of defect was made depending on; age, defect size, viability of periosteum and physes, condition of soft tissues and coexisting deformity.

Initial treatment was; plaster stabilisation (15), frame stabilisation (6), free fibula structural bone grafts (9), ipsilateral vascularised fibula graft (7), non-structural cancellous bone graft (8), bone transport (8) and amputation (4). Forty three (75%) patients were successfully treated with initial strategy. Initial treatment therefore failed in 14 (25%) patients. Successful treatment subsequently used was; structural bone grafting (6), non-structural bone grafting (4), bone transport (3) and Rush Rod stabilisation (1).

Little is known about osteomyelitis-induced bone defects, which cause massive morbidity in developing countries. Our novel research shows that these can be treated successfully, often by relatively simple methods. In the absence of ongoing infection, non-vascularised bone grafting techniques are often successful. Bone transport or vascularised grafting are more reliable but more complex solutions.

We present our experience of treating 57 cases of bone defects associated with chronic osteomyelitis (COM) and a new algorithm for their treatment.

A retrospective analysis of our operation database revealed 377 patients treated for COM (2002–2010). 76 (20%) had bone defects, of these 57 had notes and x-rays available.

Data was collected on: age, sex, type/extent of bone involved, number/type of procedures, and length of stay. The tibia was most commonly affected (63%), followed by the femur (21%). Infection control procedures included debridement, drilling and sequestrectomy. Long-term antibiotics were seldom used. Prerequisites to reconstruction surgery were; fully healed skin, absence of sequestrae on x-ray and no antibiotics for 2-months. Decision on the method of treatment of defect was made depending on; age, defect size, viability of periosteum and physes, condition of soft tissues and coexisting deformity.

Initial treatment was; plaster stabilisation (15), frame stabilisation (6), free fibula structural bone grafts (9), ipsilateral vascularised fibula graft (7), non-structural cancellous bone graft (8), bone transport (8) and amputation (4).

43 (75%) patients were successfully treated with initial strategy. Initial treatment therefore failed in 14 (25%) patients. Successful treatment subsequently used was; structural bone grafting (6), non-structural bone grafting (4), bone transport (3) and Rush Rod stabilisation (1).

Little is known about osteomyelitis-induced bone defects, which cause massive morbidity in developing countries. Our novel research shows that these can be treated successfully, often by relatively simple methods. In the absence of ongoing infection, non-vascularised bone grafting techniques are often successful. Bone transport or vascularised grafting are more reliable but more complex solutions.

Osteoarticular infections (OAI) are a common cause of morbidity in children, and as opposed to adults is usually caused by haematogenous spread. The bacteriology of OAI in children is not well described in the South African context, therefore this study was designed to determine the bacteriology of OAI in our population. All patients that underwent surgery for the treatment of OAI over a 3-year period were identified and those with positive cultures where organisms were identified from tissue, pus, fluid or blood were included. Duplicate cultures from the same patient were excluded if the organism and antibiotic susceptibility profile was the same. Patients were categorised according to age and class of infection (Septic arthritis, acute osteomyelitis, fracture related infection, post-operative sepsis and chronic osteomyelitis) and organisms were stratified according to these categories. We identified 132 organisms from 123 samples collected from 86 patients. Most cultured organisms were from children older than 3-years with acute haematogenous septic arthritis, osteomyelitis, or both. Methicillin sensitive Staphylococcus aureus accounted for 56% (74/132) of organisms cultured. There were no cases of MRSA. The Enterobacterales accounted for 17% (22/132) of organisms cultured, mostly in the fracture related and post-operative infection groups. Of these, 6 each were extended spectrum B-lactamase producers and AmpC producers. There were no carbapenemase producing Enterobacterales. Kingella kingae was not isolated in any patient. Methicillin sensitive S. aureus is the most common infecting organism in paediatric OAI and an anti-staphylococcal penicillin such as cloxacillin or flucloxacillin is the most appropriate empiric treatment for haematogenous OAI in our environment. In fracture related or post-operative infections, Enterobacterales were more frequently cultured, and treatment should be guided by culture and susceptibility results

Acute Haematogenous Osteomyelitis (AHO) remains a cause of severe illness among children. Contemporary research aims to identify predictors of acute and chronic complications. Trends in C-reactive protein (CRP) following treatment initiation may predict disease course. We have sought to identify factors associated with acute and chronic complications in the New Zealand population. A retrospective review of all patients <16 years with presumed AHO presenting to a tertiary referral centre between 2008–2018 was performed. Multivariate was analysis used to identify factors associated with an acute or chronic complication. An “acute” complication was defined as need for two or more surgical procedures, hospital stay longer than 14-days, or recurrence despite IV antibiotics. A “chronic” complication was defined as growth or limb length discrepancy, avascular necrosis, chronic osteomyelitis, pathological fracture, frozen joint or dislocation. 151 cases met inclusion criteria. The median age was 8 years (69.5% male). Within this cohort, 53 (34%) experienced an acute complication and 18 (12%) a chronic complication. Regression analysis showed that contiguous disease, delayed presentation, and failure to reduce CRP by 50% at day 4/5 predicted an acutely complicated disease course. Chronic complication was predicted by need for surgical management and failed CRP reduction by 50% at day 4/5. We conclude that CRP trends over 96 hours following commencement of treatment differentiate patients with AHO likely to experience severe disease

Introduction. Debridement, antibiotics irrigation and implant retention (DAIR) is a common management strategy for hip and knee prosthetic joint infections (PJI). However, failure rates remain high, which has led to the development of predictive tools to help determine success. These tools include KLIC and CRIME80 for acute-postoperative (AP) and acute haematogenous (AH) PJI respectively. We investigated whether these tools were applicable to a Waikato cohort. Method. We performed a retrospective cohort study that evaluated patients who underwent DAIR between January 2010 and June 2020 at Waikato Hospital. Pre-operative KLIC and CRIME80 scores were calculated and compared to success of operation. Failure was defined as: (i) need for further surgery, (ii) need for suppressive antibiotics, (iii) death due to the infection. Logistic regression models were used to calculate the area under the curve (AUC). Results. 117 eligible patients underwent DAIR, 53 in the AP cohort and 64 in the AH cohort. Failure rate at 2 years post-op was 43% in the AP cohort and 59% in the AH cohort. In the AP cohort a KLIC score of <4 had a DAIR failure rate of 28.6%, while those who scored ³4 had a failure rate of 72.2% (p=0.002). In the AH cohort a CRIME80 score of <3 had a DAIR failure rate of 48% while those who scored ³3 had a 100% failure rate (p<0.001). Discussion. This study represents the first external validation of the KLIC and CRIME80 scores for predicting DAIR failure in an Australasian population. The results indicate that both KLIC and CRIME80 scoring tools are valuable aids for the clinician seeking to determine the optimal management strategy in patients with AP or AH PJI

Aim. Debridement, antibiotics and implant retention (DAIR) has become the preferred treatment in early prosthetic joint infections (PJI) and acute haematogenous PJI, but the success rates have been varying. The aim of this study was to evaluate the outcome of a high quality DAIR procedure performed according to a consistently applied surgical protocol in early PJI's and acute haematogenous PJI's in hip and knee. Methods. We performed a prospective multicentre study in 8 hospitals in Norway. A standardized DAIR protocol was used in all patients. An empirical intravenous regimen containing cloxacillin and vancomycin was given until definitive microbiological results were known. Antibiotics were given in total for 6 weeks. The primary outcome measure was infection control. Factors that could affect the outcome were also studied. Results. Out of 99 patients included, 82 were finally analysed. 68/82 patients were successfully trreated (82,9% (CI: 74,4%-90,2%)). We found that DAIR following an infected revision arthroplasty was associated with poor outcome (59%) compares to DAIR following a primary arhroplasty (89%, p=0,007). Conclusion. The success rate of a standardized DAIR-procedure with 6 weeks of antibiotic treatment was good in PJI following primary prosthesis. The success rates following revision surgery infections are poor, and other treatment options should be considered

Introduction. Success rate after Debridement-Irrigation, Antibiotic Therapy and Implant Retention (DAIR) for treatment of Acute Haematogenous (AH) and Early Post-surgical (EP) periprosthetic joint infection (PJI) varies widely among published studies. Prosthesis exchange is recommended to treat PJI after a failed DAIR. However, no early postoperative prognostic factors permitting to identify future failures have been described. Aim. Identify early prognostic factor of failure after DAIR in order to propose efficient treatment before onset of chronic PJI. Hypothesis. Positive suction drainage fluid culture is a strong early predictive factor of failure. Methods. We conducted a retrospective study, with a minimum 2 years follow-up. Twenty-two consecutive patients (78 years-old +/-10) with EPPJI: i.e. infection within 1 month after joint replacement (n=12; 55%) or AHPJI: i.e. acute haematogenous infection with less than 2 weeks evolution (n=10; 45%) were included. The involved prostheses were: Total Knee Arthroplasty (n=12; 55%), Total Hip Arthroplasty (n=7; 32%) and Hip Hemi-Arthroplasty (n=3; 14%). DAIR was indicated for each patient. Suction drainage fluid was systematically analysed at day 1, 3 and 5 postoperative. Failure of the procedure was defined as: need for iterative surgery to control PJI or suppressive antibiotherapy to control PJI or death related to PJI. Results. At 2 years follow-up, failure rate after DAIR was 55%. Only positive suction drainage fluid culture was statistically associated with treatment failure (p=0,039). Neither type of prosthesis: knee prosthesis vs hip prosthesis (Odds Ratio (OR)=1; IC95%[0.14; 7.21]) nor type of fixation : cemented vs uncemented prothesis (OR=4,39; IC95%[0.29; 269]) were associated with treatment failure. In addition, type of bacteria causing PJI and especially S. aureus (OR=3,1; IC95%[0.42; 28.61]), type of infection (OR= 1,47; IC95%[0.21; 11.37]), delay between onset of symptoms and DAIR (OR= 1,63; IC95% [0.21; 14.85]) or retaining of modular component (OR= 1.32; IC95% [0.17; 10.59)) were not associated with a higher rate of failure. Conclusion. Positive suction drainage fluid culture could be an early postoperative predictive factor of failure after open Irrigation-Debridement, Antibiotic Therapy and Implant Retention for EPPJI and AHPJI

Aim. The liver is the major source of acute phase proteins (APPs) and serum concentrations of several APPs are widely used as markers of inflammation and infection. The aim of the present study was to explore if a local extra hepatic osseous acute phase response occurs during osteomyelitis. Method. The systemic (liver tissue and serum) and local (bone tissue) expression of several APPs during osteomyelitis was investigated with qPCR and ELISA in a porcine model of implant associated osteomyelitis (IAO) at 5, 10 and 15 days after inoculation with S. aureus or saline, respectively. Additionally, samples were also collected from normal heathy pigs and pigs with spontaneous, chronic, haematogenous osteomyelitis. Afterwards, immunohistochemistry towards different upregulated APPs was performed on the porcine osteomyelitis lesions and on bone biopsies from human patients with chronic osteomyelitis. Results. All infected porcine bone lesions (apart from Day 5 in the IAO model) were made up by necrosis, pus, and various degree of fibrotic encapsulation. A local, highly significant upregulation of Serum Amyloid A (SAA, up to 4000-fold upregulation), Complement component C3 (C3), and Inter-Alpha-Trypsin Inhibitor Heavy Chain 4 (ITIH4) were present in infected pigs compared to sterile controls. For the experimental IAO animals, the upregulation of C3 and ITIH4 increased over time, i.e., the highest expression was seen on day 15 after bacterial inoculation. In the liver, only C-reactive protein (CRP) and ITIH4 (not SAA or C3) were slightly upregulated in infected pigs. Serum concentrations of CRP, SAA and haptoglobin were only upregulated at day 5 in IAO infected animals. Immunohistochemically, comparable numbers of APP positive cells (leucocytes and bone cells) were found in human and porcine bone samples with chronic osteomyelitis. Conclusions. This is to our knowledge the first description of local APP up-regulation during chronic bone infection. Only small changes in the expression of APPs were found in the liver and serum samples. Thus, the presence of an osseous upregulation of APPs appears to be part of a predominantly local response that will be difficult to measure systemically. The importance of a local immune response in bone infections seems logical as the blood supply is severely impaired during osteomyelitis. There is a real need for supportive diagnostic bone infection criteria which should be based on a comprehensive understanding of the local inflammatory response. As seen from the present study, staining for SAA or C3 could potentially improve the diagnostic performance of histopathology

Periprosthetic joint infection (PJI) is a major complication affecting >1% of all total knee arthroplasties, with compromise in patient function and high rates of morbidity and mortality. There are also major socioeconomic implications. Diagnosis is based on a combination of clinical features, laboratory tests (including serum and articular samples) and diagnostic imaging. Once confirmed, prompt management is required to prevent propagation of the infection and further local damage. Non-operative measures include patient resuscitation, systemic antibiotics, and wound management, but operative intervention is usually required. Definitive surgical management requires open irrigation and debridement of the operative site, with or without exchange arthroplasty in either a single or two-stage approach. In all options, the patient's fitness, comorbidities and willingness for further surgery should be considered, and full intended benefits and complications openly discussed. Late infection almost invariably leads to implant removal but early infections and acute haematogenous infections can be managed with implant retention – the challenge is to retain the original implant, having eradicated infection and restored full function. Debridement with component retention: Open debridement is indicated for acute postoperative infections or acute haematogenous infections with previously well-functioning joints. To proceed with this management option the following criteria must be met: short duration of symptoms - ideally less than 2–3 weeks but up to 6; well-fixed and well-positioned prostheses; healthy surrounding soft tissues. Open debridement is therefore not an appropriate course of management if symptoms have been prolonged – greater than 6 weeks, if there is a poor soft tissue envelope and scarring, or if a revision arthroplasty would be more appropriate due to loosening or malposition of the implant. It is well documented in the literature that there is an inverse relationship between the duration of symptoms and the success of a debridement. It is thought that as the duration of symptoms increases, other factors such as patient comorbidities, soft tissue status and organism virulence play an increasingly important role in determining the outcome. There is a caveat. Based on our learning in the hip, when we see an acute infection where periprosthetic implants are used, it is much easier to use this time-limited opportunity to remove the implants and the associated biofilm and do a single-stage revision instead of just doing a debridement and a change of insert. This will clearly be experience and prosthesis-dependent but if the cementless implant is easy to remove, then it should be explanted. One critical aspect of this procedure is to use one set of instruments and drapes for the debridement and to then implant the new mobile parts and close using fresh drapes and clean instruments. Units that have gained expertise in single-stage revision will find this easier to do. After a debridement, irrigation, and change of insert, patients continue on intravenous antibiotics until appropriate cultures are available. Our multidisciplinary team and infectious disease experts then take over and will dictate antibiotic therapy thereafter. This is typically continued for a minimum of three months. Patients are monitored clinically, serologically, and particularly in relation to nutritional markers and general wellbeing. Antibiotics are stopped when the patients reach a stable level and are well in themselves. All patients are advised to re-present if they have an increase in pain or they feel unwell

Debridement, antibiotics and implant retention (DAIR) is an established treatment option for periprosthetic joint infection (PJI). Success rates of more than 90% cure have been reported with proper patient selection. While a meticulous debridement of the joint and an appropriate postoperative antibiotic therapy is important for treatment success, the relevance of changing mobile parts is still a matter of debate. The latter procedure is only possible with an extensive soft tissue release, potentially destabilizing the joint. Though, it is impossible with polyethylene-inlays being no longer available. The aim of this study was to evaluate whether cure of PJI with DAIR is influenced by retaining the mobile parts. Between 01/2004 and 12/2012, 36 patients with 39 episodes of THA-associated infections were treated with DAIR according to our algorithm (NEJM 2004). All patients met the IDSA criteria for DAIR with a stable implant and either a PJI diagnosed during the first postoperative month or a haematogenous PJI with infectious symptoms of less than three weeks. Patients were treated either with a complete debridement, including an exchange of all mobile parts (n=24), or with a complete debridement and retaining mobile parts (n=15). Postoperatively all patients received standardized antibiotic treatment (NEJM 2004). The patients’ mean age at the time of infection was 74 (SD 9) years. Average time between onset of symptoms and DAIR were 3.6 (0–28) days; Five patients died before the 2-year-follow-up unrelated to PJI. Mean follow-up of the remaining patients was 45.6 (24–119) months. 20 PJI were early postoperative, 15 haematogenously acquired, and four unclear. The most frequent causative microorganisms were coagulase-negative staphylococci (n=16), S. aureus (n=8), streptococci (n=5) and E. coli (n=2). Ten episodes were polymicrobial, and nine cases culture-negative. The overall success rate of all 39 episodes treated with DAIR was 95% (37/39). Two treatment failures were observed, both after haematogenous S. aureus infection and exchange of mobile parts. One of them refused further surgery and was treated with a suppressive antibiotic therapy. The other one had a one-stage exchange four months after DAIR showing a loose cup intraoperatively. Patients treated with DAIR strictly according to our treatment algorithm show a favourable result regarding overall success rate. From our data it seems debatable, whether the exchange of all mobile parts is mandatory, or should be individually evaluated in each case

Aim. There is a lack of both epidemiological data and of high-quality evidence to guide the management of Prosthetic joint infection (PJI). We hypothesised that there is substantial heterogeneity in the clinical presentation and management of PJI in Australia and New Zealand, and that the proportion with clinical cure at 24 months is independently associated with modifiable variables in surgical and antibiotic management. Method. Prospective binational multicentre observational study aiming to enrol 400–600 patients with large joint PJI, defined as per IDSA criteria. Following screening and written informed consent, data are collected at baseline and after 3, 12 and 24 months. The main outcome measures are clinical cure, functional status (based on Oxford joint and SF12 scores) and direct health care costs at 24 months. Results. As of April 2016, 15 sites in Australia and 5 in New Zealand have full ethics approval and have begun recruitment and over 275 patients have been recruited, of whom 59% were male and the average (SD) age was 69 (11.3) years. Obesity was common, with a mean body mass index of 32, and 23% of the cohort were diabetic. The most common joints involved were knees (55%) and hips (39%). Most infections were late postoperative acute haematogenous infections (41%), with early post-operative (<30 days) and chronic infections less common. Staphylococcus aureus was the most common causative organism (38%) and debridement and implant retention (DAIR) was the main initial management strategy (61%), with a two-stage revision the next most common (25%). The median duration of IV antibiotics was 42 days, regardless of management strategy. Rifampicin was used in only 38% overall, and in only 60% in the subgroup with Gram positive infections treated with DAIR. Conclusions. There are no generally agreed upon guidelines for the management of PJI in Australia and New Zealand, and this is reflected in heterogeneity of management strategies. Acute haematogenous infections are more common, and rifampicin use less common than expected. The PIANO study has been successfully established with minimal funding and will serve as a platform for much needed interventional studies to answer important questions about PJI management including the role of rifampicin and the timing and duration of antibiotic treatment. Acknowledgements. *PIANO Study Group – Craig Aboltins, Eugene Athan, Thi Aung, Tim Blackmore, Steve Chambers, Roy Chean, Peter Choong, Benjamin Clark, Josh Davis, Nick Graves, Steven Graves, Kate Grimwade, Garry Hooper, Paul Huggan, Justin Jackson, Chris Lemoh, Peter Leung, Mark Loewenthal, David Looke, Penny Lorenc, Christopher Luey, Laurens Manning, Stephen McBride, Sarah Metcalf, Nora Mutalima, Vana Nagendra, David Paterson, Kerry Read, Alistair Reid, Owen Robinson, Marjoree Sehu, Yuen Su, Archana Sud, Adrienne Torda, Ashley Watson and Piers Yates. The PIANO study is supported by a research grant from Hereus Medical; they played no role in study design, data analysis or the decision to publish